Light pens and other wand-type sensors that are hand-held must typically be interfaced to their receiving electronics via a cable. On small portable instrumentation, where space is at a premium, there is a problem of where to place the cable so that it is stored both safely and easily. The cable must be able to spool out freely when the wand is in use. Typically, wand cables may be straight or coiled, however, in common practice they are usually left exposed, outside of both the wand and the control electronics chassis. This presents a problem of how to store the exposed cable when the wand is not in use. Typically, the cable is simply left dangling and exposed when the wand is stored. Storage of the cable in this manner has several problems associated with it. First, the exposed cable may be damaged or simply “get in the way”. Second, the overall appearance of the assembly is not as pleasing, compact, or efficient as it could be if the exposed cable were not present. Ideally, no part of the cable should be left exposed when the wand is stored, especially for hand-held portable devices.
It is the object of this invention to overcome the disadvantages of an exposed interface cable when a wand is stored. This is achieved by incorporating a coiled cable and storing the interface cable inside the wand itself. This avoids the use of extra compartments on the electronics control chassis, and provides total protection for the stored cable, allowing for an extremely compact and efficient system design.